Species guides
The catalog, organised around the questions people actually start with: what fits the tank you have, what forgives a beginner, and what gets along.
Best Fish for a 5 Gallon Tank
46 species
Five gallons is the floor for keeping fish at all, and it is a floor, not a target — a single betta, a small group of chili rasboras, or a shrimp colony is the realistic ceiling. Water chemistry swings fast in this little volume, so every species here is one that tolerates a small planted tank rather than merely surviving it.
Best Fish for a 10 Gallon Tank
96 species
Ten gallons is where a real community becomes possible — one small school plus a bottom dweller, or a betta with company — but stocking discipline matters more here than anywhere. Every fish listed has a minimum tank size at or under ten gallons; check adult size and schooling needs before combining them.
Best Fish for a 20 Gallon Tank
96 species
Twenty gallons opens up most of the classic community fish: tetras and rasboras in proper schools, corydoras groups, dwarf gouramis, and the first larger centrepiece fish. The long twenty-gallon footprint suits active swimmers far better than the tall one.
Best Fish for a 30 Gallon Tank
96 species
Around thirty gallons you can run two or three schools with room for a centrepiece — an angelfish pair, larger gouramis, and the first cichlids that need real territory. Filtration and water changes have to scale with the extra stock, not just the extra water.
Best Fish for a 40 Gallon Tank
96 species
The forty-gallon breeder is the aquascaper's favourite footprint: shallow, wide, and stable. It comfortably houses medium cichlids, large schools, and species that need swimming length rather than height.
Best Fish for a 55 Gallon Tank
96 species
Fifty-five gallons is the entry point for fish that are simply too big or too active for smaller tanks — larger cichlids, big schools of rainbowfish, and the first plecos that stay manageable. The four-foot length matters as much as the volume.
Best Fish for a 75 Gallon Tank
96 species
At seventy-five gallons and up you are keeping fish for the fish's sake: oscars, large barbs, big plecos, and full-size cichlid communities. These species need the space as adults even if they are small when you buy them.
Best Beginner Fish
96 species
Forgiving fish tolerate the mistakes every new keeper makes — a missed water change, a temperature wobble, an over-enthusiastic feeding. These species are rated easy for exactly that reason. Start with one school, add slowly, and let the tank cycle before any of them go in.
Easy Aquarium Plants for Beginners
96 species
Easy plants grow in ordinary light without CO₂ injection and forgive irregular fertilising. Anubias, java fern, cryptocorynes and the fast stem plants here will also outcompete algae, which is the real reason to plant a new tank.
Best Shrimp for Beginners
53 species
Dwarf shrimp are easier than their reputation once the tank is mature: stable parameters matter far more than exact numbers. Neocaridina varieties top this list; the caridina species need softer, more acidic water and belong in a second tank.
Best Aquarium Snails for Beginners
51 species
Snails are the lowest-effort livestock there is — nerites for algae, mystery snails for personality, and a few that will breed whether you want them to or not. Every species here copes with ordinary community-tank water.
Peaceful Community Fish
120 species
A community tank works when nobody in it is a threat to anybody else. These species are rated peaceful: they do not nip, do not hunt, and share space with similar-sized fish. Match them on temperature and water hardness next — that is the second half of compatibility.